.secondSection {
  position: relative;
  padding-top: 56px;
}
.secondSection ul {
  top: 0;
  width: 100%;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-around;
  position: absolute;
  background-color: #e36c3f;
  font-family: SimHei;
  font-weight: bold;
}
.secondSection ul.isFixed {
  position: fixed;
}
.secondSection ul li {
  position: relative;
  color: white;
  list-style: none;
}
.secondSection ul li .line {
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  height: 4px;
  background-color: yellow;
  width: 100%;
  opacity: 0;
  transition: opacity 0.3s;
}
.secondSection ul li .line.visible {
  opacity: 1;
}
.secondSection section {
  scroll-margin: 40px;
  padding: 16px;
}
.secondSection section h2 {
  color: white;
}
.secondSection section img {
  margin-top: 16px;
  width: 100%;
  border-radius: 6px;
}
.secondSection .btnWrapper {
  position: fixed;
  height: 64px;
  padding: 0 16px;
  bottom: 0;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: linear-gradient(0deg, rgb(255, 255, 255) 0%, rgba(255, 255, 255, 0) 100%);
  opacity: 0;
  transition: opacity 0.3s, transform 0.3s;
  transform: translateY(64px);
}
.secondSection .btnWrapper.visible {
  opacity: 1;
  transform: translateY(0);
}
.secondSection .btnWrapper img {
  width: 100px;
}
.secondSection .btnWrapper button {
  border: none;
  padding: 8px 16px;
  color: white;
  border-radius: 50px;
  background: #fb7299;
}